GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2005 🢒 Vibe - FWD 🢒 Restraints 🢒 SIR 🢒 DTC B1815, B1816, B1817, or B1818

Circuit Description

The inflatable restraint instrument panel (I/P) module deployment loop consists of a dual stage inflatable restraint I/P module, the I/P module high and I/P module low circuits. There are 2 shorting bar used in the inflatable restraint I/P module connector which will short together the I/P module - high and I/P module low circuits when the connector is disconnected, this will help to prevent unwanted deployment of the inflator module during servicing. When the ignition is turned ON, the inflatable restraint sensing and diagnostic module (SDM) performs continuous diagnostic tests on the deployment loops to check for proper circuit continuity and for shorts to ground or voltage. If a malfunction is detected, a DTC will be stored.

DTC Descriptors

This diagnostic procedure supports the following DTCs:

    • DTC B1815 Passenger Air Bag Deployment Loop Resistance Too Low Circuit 2
    • DTC B1816 Passenger Air Bag Deployment Loop Resistance Too High Circuit 2
    • DTC B1817 Passenger Air Bag Deployment Loop Short To Ground Circuit 2
    • DTC B1818 Passenger Air Bag Deployment Loop Short To Battery Circuit 2

Conditions for Running the DTC

Ignition 1 voltage is within the normal operating voltage range.

Conditions for Setting the DTC

B1815

This DTC will set when the SDM detects a low resistance condition in the I/P module deployment loop.

B1816

This DTC will set when the SDM detects a high resistance condition in the I/P module deployment loop.

B1817

This DTC will set when the SDM detects a short to ground in the I/P module deployment loop.

B1818

This DTC will set when the SDM detects a short to voltage in the I/P module deployment loop.

Action Taken When the DTC Sets

The SDM commands the AIR BAG indicator ON.

Conditions for Clearing the DTC

The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.

Diagnostic Aids

Thoroughly inspect the wiring and the connectors. An incomplete inspection of the wiring and the connectors may result in a misdiagnosis, causing a part replacement with the reappearance of the malfunction.

The following are possible causes of the malfunction:

    • A short between the I/P module - high and the I/P module - low circuits
    • An open or high resistance in the I/P module - high or the I/P module - low circuits
    • A short to ground in the I/P module - high or the I/P module - low circuits
    • A short to voltage in the I/P module - high or the I/P module - low circuits
    • A malfunctioning inflatable restraint I/P module
    • An internal SDM malfunction

If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections .

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This step tests to see if the malfunction is caused by the inflatable restraint I/P module.

    2.

  2. This step tests to see if the malfunction is caused by the inflatable restraint I/P module.

    3.

  3. If DTC B1815 is present, test for a short between the I/P module high and I/P module low circuits.

    If DTC B1816 is present, test the I/P module high and I/P module low circuits for an open or high resistance.

    If DTC B1817 is present, test the I/P module high and I/P module low circuits for a short to ground.

    If DTC B1818 is present, test the I/P module high and I/P module low circuits for a short to voltage.

Step

Action

Yes

No

Schematic Reference: SIR Schematics

Connector End View Reference: SIR Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

Is DTC B1815, B1816, B1817 or B1818 set as a current DTC?

Go to Step 3

Go to Diagnostic Aids

3
  1. Turn OFF the ignition.
  2. Disconnect the instrument panel (I/P) module connector.
  3. Inspect both the component and harness sides of the connector for damage or corrosion that may cause a short between the I/P module - high and the I/P module - low circuits. Refer to Testing for Intermittent Conditions and Poor Connections .

Does the connector exhibit any signs of damage or corrosion?

Go to Step 4

Go to Step 5

4
  1. If the component side of the I/P module connector is damaged, the I/P module must be replaced. Refer to Inflatable Restraint Instrument Panel Module Replacement .
  2. If the harness side of the I/P module connector is damaged, replace the harness side of the connector. Refer to Connector Repairs .

Did you complete the replacement?

Go to Step 13

--

5

Is DTC B1816, B1817 or B1818 set as a current DTC?

Go to Step 7

Go to Step 6

6

Is DTC B1815 set as a current DTC?

Go to Step 8

--

7

  1. Connect a 3-amp fused jumper wire between the I/P module - high and the I/P module - low circuits on the harness side of the I/P module connector.
  2. Turn ON the ignition, with the engine OFF.
  3. Use the scan tool in order to Clear the DTCs.
  4. With the scan tool, request the SIR DTC display.

Does the scan tool indicate that DTC B1816, B1817, or B1818 is current?

Go to Step 9

Go to Step 11

8

  1. Turn ON the ignition, with the engine OFF.
  2. Use the scan tool in order to Clear the DTCs.
  3. With the scan tool, request the SIR DTC display.

Does the scan tool indicate that DTC B1815 is current?

Go to Step 9

Go to Step 11

9
  1. Turn OFF the ignition.
  2. Disconnect the sensing and diagnostic module (SDM) connector.
  3. Inspect the SDM connector for damage or corrosion that may cause a short between the I/P module - high and the I/P module - low circuits. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 13

Go to Step 10

10

  1. If DTC B1815 is present, test for a short between the I/P module - high and the I/P module - low circuits.
  2. If DTC B1816 is present, test the I/P module - high and the I/P module - low circuits for an open or high resistance.
  3. If DTC B1817 is present, test the I/P module - high and the I/P module - low circuits for a short to ground.
  4. If DTC B1818 is present, test the I/P module - high and the I/P module - low circuits for a short to voltage.
  5. For all of the above conditions, refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 13

Go to Step 12

11
  1. Turn OFF the ignition.
  2. Replace the I/P module. Refer to Inflatable Restraint Instrument Panel Module Replacement .

Did you complete the replacement?

Go to Step 13

--

12

Replace the SDM. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .

Did you complete the replacement?

Go to Step 13

--

13
  1. Reconnect all SIR components.
  2. Verify that all components, connectors, and connector position assurances (CPAs) are properly mounted.
  3. Use the scan tool in order to Clear the DTCs.
  4. Operate the vehicle within the Conditions for Running the DTC, as specified in the supporting text.

Does the DTC reset?

Go to Step 2

System OK